Could a 100-Year-Old Fertility Test Improve Your Chances of Conceiving?

For women facing infertility, a simple (and common) diagnostic procedure may reduce the need for IVF.

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Many women going through fertility treatments have had the dreaded hysterosalpingogram (HSG), a test that may be painful. In an HSG, dye is shot up into your Fallopian tubes and looked at with an X-ray to make sure they're open—if they're not, sperm can't get through. But the pain from the test may be worth it, as a new study in the New England Journal of Medicine shows. The HSG itself could help women conceive, especially if the fluid used in the dye is based in oil instead of water.

New confirmation for old theories

In the study, doctors randomly assigned women undergoing infertility testing to have an HSG with either water or oil-based dye. During the next six months under the care of their doctors, 40 percent of the women in the oil group got pregnant, as compared to 29 percent of the water group. "Our results have been even more exciting than we could have predicted, helping to confirm that an age-old medical technique still has an important place in modern medicine," study author Professor Ben Mol of the University of Adelaide's Robinson Research Institute in Australia said in a press release.

Doctors have debated the benefits of the test for 100 years, so this isn't exactly fresh info, says Lora Shahine, MD, a reproductive endocrinologist at Pacific NW Fertility in Seattle who was not involved in the study. "We've known since a study in 1951 that oil-based fluid used with HSG can be associated with a higher pregnancy rate in the months following the exam," Dr. Shahine tells Fit Pregnancy. "What's new about this study is the study design—a randomized controlled trial with a large number of women tested, 1119. It is a new study showing what we already know, but it is confirmation in a well-designed, large trial."

But if doctors suspected the benefits of oil-based dye, why do many use water instead? Some consider water to be safer, it may be cheaper and there wasn't concrete info proving the benefits of oil. Shahine also notes that HSGs aren't meant as treatment, but as a diagnostic tool. "I do not use it as a 'treatment'—the increased fertility is a benefit to the diagnostic test," Dr. Shahine says. "But if patients are nervous about the procedure or wondering whether or not to do it, being told it may improve chances of conception can help them decide to do it."

Doctors still don't know why it works

Although the exact reason the HSG helps conception aren't known, there are some ideas. "The theory is that the flushing of the tubes with the fluid will unblock the tubes, flushing out any potential debris that may impact the ability of egg and sperm to find each other in the tube for fertilization—like flushing a pipe," Dr. Shahine says.

This study shows the procedure could help couples get pregnant before resorting to expensive and invasive treatments like IVF. "I've learned that patients are more fertile, more likely to conceive for the three months following HSG," Dr. Shahine says. The study authors think it could used beyond a diagnostic tool as a potential treatment option—especially if patients talk to their doctors about using the oil-based fluid. "Further research would need to be conducted into the mechanisms behind what we're seeing," Professor Mol says. "For now, and considering the technique has been used for 100 years without any known side effects, we believe it is a viable treatment for infertility prior to couples seeking IVF."